veyron-browser: use a shortername for tmp so https://code.google.com/p/chromium/issues/detail?id=441414 does not kick in.
veyron-browser: use a shortername for tmp so
https://code.google.com/p/chromium/issues/detail?id=441414 does not kick in.

Change-Id: I727a0aaca53e0b80924f83af2c93af18d8a7cfd3

vanadium/browser,vanadium/browser,vanadium/browser,vanadium/browser